Case report

A 30 year old woman was referred to our specialist glaucoma clinic with a diagnosis of aphakic glaucoma in her right eye. She had a past ophthalmic history of chronic uveitis secondary to juvenile chronic arthritis, complicated right cataract surgery and subsequent aphakic glaucoma.

At the time of referral her visual acuities were 6/36 in her right aphakic eye and 6/5 in the left eye. She had an IOP of 19 mm Hg in her right eye and significant glaucomatous disc cupping (cup:disc ratio 0.85). Her right IOP was controlled with dorzolamide eye drops 2%, carteolol eye drops 2%, both twice a day, and latanoprost eye drops 0.005% at night. Our patient wanted to become pregnant but was justifiably concerned that the topical medication she was using might affect her pregnancy. It was decided that we would perform cyclodiode laser therapy on her right eye, under peribulbar anaesthesia, and stop her topical antiglaucomatous therapy. The first session of cyclodiode (1500 mW × 1500 ms × 40 shots over 360° with 3 and 9 o’clock sparing) was unsuccessful and 6 weeks later her IOP was 33 mm Hg on no ocular hypotensive therapy. The second session of cyclodiode therapy (2000 mW × 2000 ms × 40 shots) was partially successful, the IOP being 22 mm Hg 6 weeks later, although this had risen to 28 mm Hg by 4 months. By this time our patient had become pregnant and it was felt that the IOP was still too high. A third attempt at lowering IOP by cyclodiode (2000 mW × 2000 ms × 40 shots over 360°) was made, following which the IOP was persistently well controlled at 12–14 mm Hg.

Comment

The use of cyclodiode laser therapy to control IOP in women before and during pregnancy has not been described. It seems a rational choice in treating these patients since the use of topical antiglaucomatous therapy is either contraindicated or cautioned in pregnancy.¹ β Blockers, sympathomimetics, carbonic anhydrase inhibitors, parasympathetomimetics, apraclonidine, and prostaglandin analogues have all been shown to have adverse effects in animal fetal models.^1,2 Understandably, there have been no equivalent studies in the human fetus and resulting teratogenesis in laboratory animals cannot be extrapolated to humans.³ However, some specific examples of adverse effects related to specific topical medications have been quoted in the literature.^2,4,5 Topical timolol has been shown to cause fetal cardiac arrhythmia and bradycardia.⁴ There has been one reported case that correlates the use of acetazolamide in early pregnancy with sacrococcygeal teratoma in the neonate.⁵ Prostaglandins are involved in the physiology of pregnancy and thus the use of latanoprost is not advised during pregnancy.²

Pregnancy is usually a period of lower IOP⁶ and less therapy may be required than before gestation, although that was not the case with our patient. It could be argued that optic nerve damage over a 9 month period would be minimal such that a mildly raised IOP could be tolerated for the length of pregnancy. However, when glaucomatous damage is severe, it is generally accepted that a low target IOP should be attained.

There is a paucity of literature describing the use of local anaesthetics for ophthalmic procedures during pregnancy. However, in a large multicentre retrospective study, exposure to local anaesthetic during early pregnancy resulted in no increased incidence of fetal malformation.⁷ Our patient could have been offered augmented filtration or tube implantation surgery but cyclodiode was felt to be less invasive and, ideally, exposure to antimetabolites should be avoided in pregnancy.²

Cyclodiode is a safe and effective treatment to control IOP before and during pregnancy. The risk of topical medication to the fetus is eliminated and more complex surgical intervention with general anaesthesia is avoided.